There is no silver bullet to deal with disease in any given crop. But we can recommend an integrated pest management approach in every case. This includes physical, cultural, biological and chemical control. Ensure you’ve chosen the right control measures for the disease, and make sure to get your timing and coverage right. We’ve chosen some of the top disease challenges you’re likely to face in canola, pulses, and cereals and have paired them with our best recommendations for control. *Always read and follow label directions.
Choose the right solution for the disease
Blackleg
Difficulty Rating: Medium
Blackleg is caused by the fungus Leptosphaeria maculans that are present in the field on infected canola stubble. The fungus produces spores that enter canola plants through broken tissue caused by hail or insect feeding. A distinct pale lesion with pepper-like pycnidia spots will form. The fungus travels through the stem to the base where it enters vascular tissue causing nutrient and water deficiencies and necrosis. The plants will prematurely ripen or die, which can cause significant yield loss. Genetic resistance is the best method for long-term control. But also use a three to four-year rotation between canola crops to allow the disease to break down fully. Control weeds such as volunteer canola and wild mustard that can also host the disease.
Top Fungicides
Priaxor®
Groups 7,11
Active Ingredient: Fluxapyroxad, Pyraclostrobin
Apply at the 2-6 leaf stage. Scout early and often for blackleg, especially in warm, humid conditions. Look at 50 plants in a W pattern through the field and apply fungicide to suppress the disease if lesions are found on more than 10% of plants. Earlier timing has the greatest chance of reducing the incidence of the disease.
Quilt®
Groups 3,11
Active Ingredient: Azoxystrobin, Propiconazole
Apply at the 2 leadf to bolting stage. Scout early and often for blackleg, especially in warm, humid conditions. Look at 50 plants in a W pattern through the field and apply fungicide to suppress the disease if lesions are found on more than 10% of plants. Earlier timing has the greatest chance of reducing the incidence of the disease.
Sclerotinia Stem Rot
Difficulty Rating: Medium
Sclerotinia Stem Rot is a soil borne disease most commonly found in canola but also in peas, lentils, beans, mustard and sunflowers. Infection happens around flowering when rain washes spores from falling petals and lands on leaves below. Sclerotinia grows into the stem, causing it to die and become brittle as sclerotia develop inside. The death of the stem causes premature ripening and shelling and can cause up to 50% loss in yield. Rotation can help control sclerotinia. Grow non-host species such as cereals prior to canola and avoid other susceptible crops. Sclerotia can remain in the soil for up to five years.
Top Fungicides
Proline® 480 SC
Group 3
Active ingredient: Prothioconazole
Apply at 20-50% flower. Ideal fungicide spray timing is at 30% bloom to soak the maximum number of petals before they drop.
Cotegra®
Groups 3,7
Active ingredient: Boscalid, Prothioconazole
Apply at 20-50% flower. Ideal fungicide spray timing is at 30% bloom to soak the maximum number of petals before they drop. Consider a second pass in 7 to 14 days after first application if you: 1. Have a crop worth protecting with high yield potential. 2. See continued high disease pressure. 3. Have a history of sclerotinia. 4. Seeded into stubble of a susceptible crop or rotations are tight.
Lance® AG
Groups 7,11
Active ingredient: Boscalid
Apply at 20-50% flower. Ideal fungicide spray timing is at 30% bloom to soak the maximum number of petals before they drop. Consider a second pass in 7 to 14 days after first application if you: 1. Have a crop worth protecting with high yield potential. 2. See continued high disease pressure. 3. Have a history of sclerotinia. 4. Seeded into stubble of a susceptible crop or rotations are tight.
Fusarium Head Blight
Difficulty Rating: Medium
Fusarium head blight (FHB) is a fungal disease that affects kernel development, in turn reducing yield and grade. It overwinters in crop residues of small grain cereals and corn and appears under moist conditions and temperatures of 25-30°C. FHB can contaminate grain with a mycotoxin produced in infected seeds that can render grain unfit for animal or human consumption. Grain from blighted heads are often shriveled and chalky white, or wheat kernels can have a light pink/white mould on them. Spores will be released for up to two days following moisture and are spread by wind and splashing water droplets. Take a two-year break between cereal crops, use clean seed and seed treatments can also improve germination of infected seed.
Top Fungicides
Prosaro® XTR
Group 3
Active ingredient: Prothioconazole, Tebuconazole
For suppression of FHB in wheat apply when at least 75% of the wheat heads on main stems are fully emerged to when 50% of the heads on the main stem are in flower. Optimal timing for fungicide is when flowering begins and you can see yellow anthers in the middle of wheat heads.
Caramba®
Group 3
Active ingredient: Metconazole
For suppression of FHB in wheat apply when at least 75% of the wheat heads on main stems are fully emerged to when 50% of the heads on the main stem are in flower. Optimal timing for fungicide is when flowering begins and you can see yellow anthers in the middle of wheat heads.
Miravis® Ace
Groups 3,7
Active ingredient: Propiconazole, Pydiflumetofen
For suppression of FHB in wheat (spring, winter, durum) apply when at least 75% of the wheat heads on main stems are fully emerged to when 50% of the heads on the main stem are in flower. Optimal timing for fungicide is when flowering begins and you can see yellow anthers in the middle of wheat heads.
Tan Spot
Difficulty Rating: Medium
Tan Spot (also known as yellow leaf spot) spores spread by wind from overwintering structures in crop residue. Small, dark brown to black spots first appear on lower leaves. Tan, oval-shaped lesions develop along the veins and a central dark spot with a light halo is often present. Tan spot reduces the photosynthetic area of the leaves and may cause yield loss, particularly when upper leaves are affected. Conidia are produced on old lesions on wet leaves and becomes air borne as the leaves dry. The fungus requires six hours of leaf wetness to infect and colonize new leaf tissue. Don’t confuse tan spot and Septoria symptoms, which look very similar. Remember tan spot lesions never develop pycnidia (fruiting bodies). Wheat grown in Canada is susceptible to both tan spot and Septoria, so rotation to non-host crops - canola, flax, corn, soybeans, potatoes or alfalfa can help.
Top Fungicides
Nexicor™
Groups 3,7,11
Active ingredient: Fluxapyroxad, Pyraclostrobin, Propiconazole
Nexicor can be applied to manage tan spot in wheat from stem elongation until early head emergence. We recommend you apply at flag leaf. Fungicides don’t have much curative action and are only effective when you follow the label and spray at the correct stage to provide the best protection against cereal leaf diseases.
Trivapro®
Active ingredient: Solatenol, Azoxystrobin, Propiconazole
Apply Trivapro in cereals (barley, wheat, oats) between stem elongation and head half emergence up until the flag leaf stage. We recommend applying at flag leaf. Fungicides don’t have much curative action and are only effective when you follow the label and spray at the correct stage to provide the best protection against cereal leaf diseases.
Quilt®
Active ingredient: Azoxystrobin, Propiconazole
Apply Quilt in cereals at early flag leaf stage to protect the flag leaf from a number of leaf diseases that can reduce grain quality and yield. Fungicides don’t have much curative action and are only effective when you follow the label and spray at the correct stage to provide the best protection against cereal leaf diseases.
Septoria Complex
Difficulty Rating: Medium
This complex of diseases affects wheat and other cereals. Symptoms initially appear as yellow flecks which soon enlarge to become oval blotches. Then the fruiting bodies (pycnidia) of the fungus develop in the blotches and appear as dark specks. The fungus overwinters in crop residue and spores produced in early summer can infect the new crop, spreading during wet, windy weather with temperatures of 15-27°C when spores are splashed by rain to other leaves and plants. This disease can cause shriveled grain and reduce yield. Wheat grown in Canada is susceptible to both tan spot and Septoria so rotation to non-host crops -- canola, flax, corn, soybeans, potatoes or alfalfa can help.
Top Fungicides
Nexicor™
Active ingredient: Fluxapyroxad, Pyraclostrobin, Propiconazole
Nexicor can be applied from stem elongation until early head emergence. We recommend you apply at flag leaf. Fungicides don’t have much curative action and are only effective when you follow the label and spray at the correct stage to provide the best protection against cereal leaf diseases.
Trivapro®
Active ingredient: Solatenol, Azoxystrobin, Propiconazole
Apply Trivapro between stem elongation and head half emergence up until the flag leaf stage. We recommend applying at flag leaf. Fungicides don’t have much curative action and are only effective when you follow the label and spray at the correct stage to provide the best protection against cereal leaf diseases.
Quilt®
Active ingredient: Azoxystrobin, Propiconazole
Apply Quilt at early flag leaf stage to protect the flag leaf from a number of leaf diseases that can reduce grain quality and yield. Fungicides don’t have much curative action and are only effective when you follow the label and spray at the correct stage to provide the best protection against cereal leaf diseases.
Anthracnose
Difficulty Rating: High
The anthracnose pathogen is carried on lentil stubble. Microsclerotia on the soil surface are rain splashed onto lower plant leaves and stem. Spores spread through rain splash, and white to grey, oval lesions develop on lower leaves in warm conditions. Patches in the field will appear yellow as disease slowly kills the plants. Microsclerotia remain viable in the soil for four years and can spread when stubble are blown in the wind. Faba beans and wild vetch also host anthracnose. Rotate four years between lentils and eliminate lentil volunteers to help keep your crop clean of anthracnose.
Top Fungicides
Priaxor®
Groups 7,11
Active ingredient: Fluxapyroxad, Pyraclostrobin
Apply in lentils at a rate of 80 acres per jug at the onset of symptoms and up to the beginning of flowering. You are at higher risk of encountering resistance if you rotate pulse crops every two-three years, if you always use Group 11 fungicides, if you cut fungicide rates, if you have neighbouring fields with confirmed resistance, or if you’ve had high anthracnose pressure in previous years.
Dyax®
Active ingredient: Fluxapyroxad, Pyraclostrobin
Apply in lentils at a rate of 60 acres per jug at the onset of symptoms and up to the beginning of flowering. You are at higher risk of encountering resistance if you rotate pulse crops every two-three years, if you always use Group 11 fungicides, if you cut fungicide rates, if you have neighbouring fields with confirmed resistance, or if you’ve had high anthracnose pressure in previous years.
Elatus™
Active ingredient: Solatenol, Azoxystrobin
Apply in lentils at or before disease establishment, up to the beginning of flowering or row closure. You are at higher risk of encountering resistance if you rotate pulse crops every two-three years, if you always use Group 11 fungicides, if you cut fungicide rates, if you have neighbouring fields with confirmed resistance, or if you’ve had high anthracnose pressure in previous years.
Delaro®
Groups 3,11
Active ingredient: Prothioconazole, Trifloxystrobin
Apply in lentils at a rate of 20 acres per jug at the first sign of disease. You are at higher risk of encountering resistance if you rotate pulse crops every two-three years, if you always use Group 11 fungicides, if you cut fungicide rates, if you have neighbouring fields with confirmed resistance, or if you’ve had high anthracnose pressure in previous years.
Mycosphaerella (Asochyta) Blight
Difficulty Rating: Medium
Mycosphaerella blight is the most common disease found in peas in western Canada. It is seed, stubble, and soil borne and can survive several years in seed or as resting spores in the soil. Infection typically happens under cool, wet conditions when the emerging seedlings come in contact with resting spores, then the pathogen grows from the seed into the stem. Infested crop residue is the most common source of disease. The pathogen typically attacks leaves, stems, flowers, and pods. Early symptoms include small, purplish-black spots that enlarge. It can cause yield losses of more than 30%.
Top Fungicides
Dyax®
Groups 7,11
Active ingredient: Fluxapyroxad, Pyraclostrobin
Apply in peas at the onset of symptoms and prior to row closure at the beginning of flower. Consider a second pass if disease pressure is severe or conditions are conducive to disease development. Remember to rotate fungicide modes of action and never use cut rates of fungicides to prevent the development of fungicide resistance.
Delaro®
Groups 3,11
Active ingredient: Prothioconazole, Trifloxystrobin
Apply at the onset of symptoms and prior to row closure at the beginning of flower. Consider a second pass if disease pressure is severe or conditions are conducive to disease development. Remember to rotate fungicide modes of action and never use cut rates of fungicides to prevent the development of fungicide resistance.
Elatus®
Groups 7,11
Active ingredient: Azoxystrobin, Solatenol
Apply at the onset of symptoms and prior to row closure at the beginning of flower. Consider a second pass if disease pressure is severe or conditions are conducive to disease development. Remember to rotate fungicide modes of action and never use cut rates of fungicides to prevent the development of fungicide resistance.
Aphanomyces
Difficulty Rating: High
Aphanomyces is a root rot that affects peas and lentils. Usually this disease will show up in a complex of other root rots so it makes it difficult to identify, but it is distinguished by caramel coloured roots. A plant can become infected at any time and in early stages of pulse development, it can cause death of the plant. In later infections, you will see severe lodging and poor yield. This pathogen is a water mould and requires moisture for infection. Aphanomyces is difficult to manage because you cannot spray for it, and seed treatments cover the crop for a limited time. Include faba beans or chickpeas, which have partial and moderate resistance respectively, or soybeans, which are fully resistant, as alternative legume crops in your rotation.
Top Fungicides
There are no spray fungicides registered to control Aphanomyces at this time.
Intego® Solo (seed treatment)
Acitve ingredient: Ethaboxam
Intego Solo will only control early season infection. The plant will be susceptible after the seed treatment has worn off later in the season. Lengthen rotation between host crops and avoid planting peas on heavier pieces of land. Try to eliminate any reason for standing water or poor water movement in the soil.
- Choose your crop
- What disease are you dealing with?